public class Example4_10 {
   public static void main(String args[]) {
      Lader.下底 = 100;
      Lader laderOne = new Lader();
      Lader laderTwo = new Lader();
      laderOne.设置上底(28);
      laderTwo.设置上底(66);
      System.out.println("laderOne的上底："+laderOne.获取上底());
      System.out.println("laderOne的下底："+laderOne.获取下底());
      System.out.println("laderTwo的上底："+laderTwo.获取上底());
      System.out.println("laderTwo的下底："+laderTwo.获取下底());
   }
}
